Landscape Boulders & Slabs Estimating Guide
Stone Calculations

Boulders: large to very large stones that may be rounded or angular, and of limestone, sandstone or granite

Slabs: or what are sometimes referred to as outcroppings, are large flattish pieces of natural stone

Coverage Calculation:

Single Round Boulders: in feet, calculate the area of a sphere of the approximate diameter of a desired boulder (A = 4/3 x Pi x radius cubed). Note: An ellipsoid of the same diameter and twice the length of a sphere, equal two times the volume of the sphere.

Angular Boulders: use the slab method below

Single Slab: in feet, calculate the average thickness x average length x average width = cubic feet

Wall: in feet, calculate the average height x average depth x average length = cubic feet

Cubic Feet Weight:

Limestone = 165 pounds

Sandstone = 150 pounds

Granite = 175 pounds